sampling what rdtsc reports for the clock frequency (often wrong)

main.rs

fn ticks() -> u64 {
    let mut discard = 0;
    unsafe { core::arch::x86_64::__rdtscp(&mut discard) }
}

fn main() {
    let t0 = std::time::Instant::now();
    let c0 = ticks();
    std::thread::sleep(std::time::Duration::from_secs(1));
    let t1 = std::time::Instant::now();
    let c1 = ticks();

    let t_diff = t1 - t0;
    let c_diff = c1 - c0;
    dbg!(t_diff);
    dbg!(c_diff);
    let ghz = c_diff as f64 / t_diff.as_nanos() as f64;
    dbg!(ghz);
}